ERI Seminar Series: "Pathways of carbon sequestration by carbohydrates in the ocean"

Seminar Abstract:

Oxygenic photosynthesis yields carbohydrates, the most abundant group of organic molecules on the planet. While chemically simple carbohydrate polymers or glycans serve as energy storage and structure, glycans involved in signalling and defence feature high chemical complexity. In this talk, I will summarize our recent findings on the secretion of the complex glycan fucoidan by brown algae into the ocean’s dissolved organic carbon pool. These results relied on the development of quantitative tools to measure fucoidan in seawater, including extraction of fucoidan, enzymatic depolymerization and specific antibody recognition. Due to the high complexity, microorganisms struggle to degrade brown algal fucoidan. Combined with evidence of fucoidan in centuries-old sediments, this suggests that fucoidan can form a significant carbon sink in the ocean.

Speaker Bio:

After working in central Chile on the ecophysiology of intertidal algae species and their response to heatwaves, Hagen Buck-Wiese studied Biology at the University of Bremen and the University of the Antilles. Following a project on microbial coral diseases, he joined the Max Planck Institute for Marine Microbiology for a master’s degree and continued with a PhD project on the role of glycan complexity for their potential to sequester organic carbon in the ocean. The study he will focus on during the talk arose from an EU-funded young researcher grant called Assemble Plus that he did during my PhD on the release of organic molecules from seagrass and brown algae in Finland.